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Old 02-28-2014, 02:54 PM   #1
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Hi Everyone.

I thought I would start this thread where you can post setup questions and I will do my best to answer them. Based on the volume of questions in the "Traction Rolling" thread, I thought this might be a good idea.

Cheers.
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Old 02-28-2014, 03:22 PM   #2
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Great idea Martin!

With ETS being in such low grip, I see comments that the pros are trying things like no sway bars, softer oil, more flex, but harder springs. What are your thoughts on setup for low grip conditions?
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Old 02-28-2014, 03:25 PM   #3
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Okay, here we go: What are the 2 most effective adjustments to keep the front tires on a touring car from overheating on an indoor carpet track?
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Old 02-28-2014, 03:34 PM   #4
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Originally Posted by CraigM View Post
Great idea Martin!

With ETS being in such low grip, I see comments that the pros are trying things like no sway bars, softer oil, more flex, but harder springs. What are your thoughts on setup for low grip conditions?
Backdoor-ing on this question... I am a pan-car racer with pretty limited sedan experience. The other weekend I ran sedan at our local parking lot track and suffered from on-power loose-ness all day long. Nothing I did fixed the problem... and some things, such as going to a softer rear spring(from a ~14.5lb/in to 12.0lb/in spring), actually made the problem worse.

Some of the things I tried:
* Longer rear wheelbase
* Pulled screws out of top-deck @ layshaft/motor mount
* Softer rear springs
* Going from 3 to 3.5deg rear toe - this was the only thing that felt like a real step in the right direction
* More front droop

Things I wanted to try but didn't get around to:
* Lighter rear diff oil(was running 1500cst or thereabouts)
* Camber changes(was running 2.0front, 1.5 rear)

Any thoughts on where I should turn next?
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Old 02-28-2014, 04:08 PM   #5
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Originally Posted by CraigM View Post
Great idea Martin!

With ETS being in such low grip, I see comments that the pros are trying things like no sway bars, softer oil, more flex, but harder springs. What are your thoughts on setup for low grip conditions?
In general having a softer setup is better for low grip, because it allows you to control more longitudinal weight transfer with throttle and brake, so you can get the car to rotate off power into a corner and also still be stable when you apply power out of a corner. Unfortunately that also allows more lateral weight transfer which will actually reduce your overall lateral grip, but at least you can control the balance of the car. But you can offset this lateral weight transfer issue with roll center as discussed in the next paragraph.

Another very important thing to do is to raise the roll centers both front and rear. Perhaps take out 1mm to 2mm of the inboard spacers on the upper links for example. It tends to offset the softer setups (i.e. softer springs / swaybars) in that it helps reduce lateral roll giving you better lateral grip. But it still allows for good longitudinal weight transfer (ie. front to rear to front) which still allows you to control the weight transfer (and thus balance) with your throttle.


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Originally Posted by Colbynobo View Post
Okay, here we go: What are the 2 most effective adjustments to keep the front tires on a touring car from overheating on an indoor carpet track?
hard question to answer as it depends on what your entire setup is. But if I had to provide an answer.....

If you front tires are over heating more than your rears, then you likely have too much of a push in the car, so any changes that help you get rid of a push would be good things to try. But you need to know if your car is pushing on corner entry , middle or corner exit to fine tune which adjustments to make. For example if your car is pushing in the middle and exit of the corner, you can try raising the front roll center in combination with a slightly softer spring in the front.

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Originally Posted by JamesL_71 View Post
Backdoor-ing on this question... I am a pan-car racer with pretty limited sedan experience. The other weekend I ran sedan at our local parking lot track and suffered from on-power loose-ness all day long. Nothing I did fixed the problem... and some things, such as going to a softer rear spring(from a ~14.5lb/in to 12.0lb/in spring), actually made the problem worse.

Some of the things I tried:
* Longer rear wheelbase
* Pulled screws out of top-deck @ layshaft/motor mount
* Softer rear springs
* Going from 3 to 3.5deg rear toe - this was the only thing that felt like a real step in the right direction
* More front droop

Things I wanted to try but didn't get around to:
* Lighter rear diff oil(was running 1500cst or thereabouts)
* Camber changes(was running 2.0front, 1.5 rear)

Any thoughts on where I should turn next?
You are on the right track with your thinking. I would run not more than 1000cst in the rear diff, 2 degrees rear camber and 1.5 degrees front camber (ie. reverse of what you have now) and would also raise the rear roll center by removing 1mm to 2mm worth of spacers on the inboard connection of the upper link or adding the same amount on the outboard connection of the upper link.

The lighter diff oil will reduce on power sliding from the rear.

More rear camber and less front camber will give the rear more grip through out the corner.

A higher rear roll center will give the rear more grip.

Re: the lower spring rates -> yes you can go too soft and make things worse because you are allowing the rear to roll way more than the front of the car assuming you had something like an 18+lb spring on the front. By raising the rear roll center it will help reduce the lateral roll caused by the softer springs, so you get the best of both worlds...i.e you get the weight transfer to the rear, but you also reduce the lateral roll of the rear...the combination will give you more rear grip.

Increasing the rear toe will help as you indicated, but 3.5 degrees is a lot. I have never had to go beyond 3 degrees.

Hope this helps guys.

Cheers,
Martin.
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Old 02-28-2014, 04:17 PM   #6
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I've found the opposite is sometimes true.


(I know that's straight from your app)

4k diff fluid calmed my car down from 2k
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Old 02-28-2014, 06:13 PM   #7
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Originally Posted by R3VoLuTiOn View Post
I've found the opposite is sometimes true.


(I know that's straight from your app)

4k diff fluid calmed my car down from 2k
Always important to try different things.
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Old 02-28-2014, 07:12 PM   #8
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You deserve a pat on the back for the things you have done to help racers unlock the mysteries of TC physics and handling.
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Old 02-28-2014, 07:23 PM   #9
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Hi Martin, I have a question about the sway bars on my T3 2012. With the shocks disconnected I can lift the left front arm almost all the way up until the right front arm moves. When I lift the right front arm up about a 1/4 inch the left arm moves up. The linkage that connects the bar to the arms are equal lenght and the bar doesn't seem bound, what can I do to get the arms to move equally? I have tried adjusting the length of the links but it didn't help.
Thanks for your time.
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Old 02-28-2014, 08:09 PM   #10
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Question regarding link length-

Say that without changing anything else on the car, what if I go from a long link in the front to a short one. And then the same scenario, but applied to to the rear of the car. Basically, what change in the cars handling can be expected?
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Old 02-28-2014, 08:44 PM   #11
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Originally Posted by nf_ekt View Post
Question regarding link length-

Say that without changing anything else on the car, what if I go from a long link in the front to a short one. And then the same scenario, but applied to to the rear of the car. Basically, what change in the cars handling can be expected?
^^^good question^^^ ive never really understood the link length question.
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Old 02-28-2014, 08:57 PM   #12
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Quote:
Originally Posted by snoopyrc View Post
You deserve a pat on the back for the things you have done to help racers unlock the mysteries of TC physics and handling.
Thank you

Quote:
Originally Posted by outlandr91 View Post
Hi Martin, I have a question about the sway bars on my T3 2012. With the shocks disconnected I can lift the left front arm almost all the way up until the right front arm moves. When I lift the right front arm up about a 1/4 inch the left arm moves up. The linkage that connects the bar to the arms are equal lenght and the bar doesn't seem bound, what can I do to get the arms to move equally? I have tried adjusting the length of the links but it didn't help.
Thanks for your time.
Great question. First it is very very important that you get the same amount of lift on both sides, otherwise your car will handle very differently left and right. You will need to adjust the linkage lengths to achieve this balance. You will want to shorten the linkage on your right arm to make yours more balanced. Also make sure you set your droop first on both arms so they are identical before you make any changes...just to ensure a difference in droop is not masking something.

Quote:
Originally Posted by nf_ekt View Post
Question regarding link length-

Say that without changing anything else on the car, what if I go from a long link in the front to a short one. And then the same scenario, but applied to to the rear of the car. Basically, what change in the cars handling can be expected?
The link length will affect both the roll center and the camber gain, but the dominant affect is on the camber gain. The shorter the upper link the more camber gain (increase in negative camber) you will get as the suspension is compressed. This increase in camber gain will typically give that end of the car more grip in the corner. If you already have a lot of camber then more camber gain in the corner would actually take away grip because the contact patch becomes smaller, but in reality this wont happen with the amount of camber we typically run on our touring cars (i.e. between 1 to 2.5 degrees.

So if you shorten the front upper links you will get more steering. If you shorten the rear upper links your car will have less steering and more rear grip.

Cheers.
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Old 03-01-2014, 02:24 AM   #13
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It's an interesting discussion regarding the general hardness or softness of the car depending on grip levels. For example above we are talking about a soft car in low grip conditions for valid reasons to the extent of running without ARB's.

At TITC last week the traction was incredibly high. Higher than I've ever seen. Traction roll was a big problem and I went for a stiff car to try to counteract it - I ended up with a very nervous car that was difficult to drive. The best thing I found was maintaining the heavy dampening and rear diff simply going down 3 grades of springs softer all round made a massive difference and almost eliminated the traction roll problem and making the car very easy to drive. Lap times were the same but I was more consistent.

One of the biggest things I've found helps is chassis flex. High flex in low traction and little or zero flex in high grip conditions almost make more influence than shocks/springs.

How does this stack up with theory Martin?? Thanks for all your hard work - I'm signed up to the new website. It's brilliant!
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Old 03-01-2014, 02:25 AM   #14
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MODS can this thread be made a sticky please??
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Old 03-01-2014, 04:18 AM   #15
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Subscribed !! Very, very informative thread....
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